1. Field of the Invention
The present invention relates generally to an apparatus for opening the sliding gates of a railway hopper car, and, in particular, to a novel apparatus for simultaneously opening all of the sliding gates of a railway hopper car, regardless of the direction in which the gate is moved.
2. Description of the Prior Art
A common type of railroad freight car in use today is the covered freight car of the type wherein the load is discharged through sliding doors, which are also known as sliding gates, on the underside of the body. Such cars are generally referred to as covered hopper cars and are used to haul grain, phosphate, plastic, and other dry bulk commodities that require protection from natural elements.
After covered hopper cars are spotted over an unloading pit, the sliding gates on the bottoms of the cars are presently opened and closed by either of two methods: Each gate can be manually cranked open or closed with a steel bar that is inserted into a fitting on the gate, one gate at a time; or, each gate can be opened and closed by manually applying a rotary drive air wrench to the same fitting on the gate, one gate at a time. While either of these methods will open the gates and allow the covered hopper to unload, both are time consuming because of the manual operation and because of the need to open each gate individually. Moreover, both methods are labor intensive and expose to injury those persons who are manually opening the sliding gates.
The problem of safely and efficiently unloading hopper cars has been addressed previously.
U.S. Pat. No. 3,633,515, issued to Shaver et al., describes a power operated door opening and closing mechanism for rotating doors; U.S. Pat. No. 3,596,609, issued to Ortner et al., describes a system for simultaneously opening rotating hopper doors. U.S. Pat. No. 3,348,501, issued to Stevens et al., describes a sliding gate system, individually activated, for discharging the hopper contents through either one large opening or two smaller side-by-side openings; French Pat. No. 1,188,761 describes a sliding gate system which automatically opens all the sliding gates of a railway car in one direction.
However, none of the above systems address the problem of opening the sliding gates on a hopper car when some of the gates must be moved in opposite directions. This problem occurs in a significant number of railway hopper cars having two, three, or four sliding gates. To avoid interference with the railcar's trucks, the gates are positioned such that at least one of the sliding gates moves in an opposing direction to the movement of the other gates.